Lock



Jly 2l, 1936. E. N. JAcoBl v 2 Sheets-Sheet 1 Filed Nov. 3, 1953 July 21, 1936.

E. N. .lAcoBl 2,047,966

LOCK

2 Sheets-Sheet 2 Filed Nov. s, 1955 I 9 l UWWd/ L7551727/ Patented July 21, 1936 vPATENT OFFICE LOCK Edward N. Jacobi, Milwaukee, Wis., assignor to Briggs & Stratton Corporation, Milwaukee, Wis., a corporation of Delaware Application November 3, 1933, Serial No. 696,467

18 Claims.

This invention relates to certain new and useful improvements in locks and refers more particularly to keycontrolled tumbler locks.

It is a general. object of this invention to pro-V A vide a lock having greater security against unauthorized opening either by picking or decoding, then locks heretofore in use.

Another object of this invention is to provide a lock in which the tumblers project in opposite directions to insure greater security against forced opening and in which the tumblers are arranged in pairs with a single spring for each pair.

Another object of this invention is to provide protection against destruction of the lock by drilling out the tumblers. y

Another object of this invention is to utilize the means affording protection against drilling for guiding the key into proper engagement with the tumblers and for limiting the movement of the tumblers by their urging springs.

Another object of this invention is to position the key guiding and tumbler stopping rib so as to divide the keyway into substantially separated chambers of such restricted size that operation 'of a picking tool therein is extremely diiiicult if not entirely impossible.

With the above and other objects in View which will appear as the description proceeds, my invention resides in the novel construction, combination and arrangement of parts substantially as hereinafter described and more particularly dened by the appended claims, it being understood that such changes in the precise embodiment of the hereindisclosed invention may be made as come within the scope of the claims.

In the accompanying drawings, vI have illustrated two complete examples of the physical embodiment lof my invention constructed ac- 40 ccrding to the best modes I have so far devised for the practical application of the principles thereof, and in which:

Figure 1 is a view partly in side elevation and partly in section of a lock embodying this in- 45 vention; Y Figure 2 is a cross section view taken through 'Figure 1 on the plane of the line -2-2;

Figure 3 is a transverse section view taken through Figure 1 on the plane of the line 3 3; Figure 4 is a perspective view illustrating a de' tail of the lock 'cylinder construction;

Figure 5 is a perspective view of the keyemployed in the lock shown in Figure 1;

VVFigure 6 is a detail 'section view through the (Cl. 'l0-46) key taken on the plane of the line 6 6 of Figure 5;

Figures 7, 8 and 9 are perspective views showing various stages in the formation of the tumblers;

Figure 10 is a perspective view of all of the tumblers assembled with the key guide;

Figure 11 is a cross section view similar to Figure 2, but illustrating a Slightly modied form of this invention; and

Figure12 is a perspective view of the key employed in the embodiment shown in Figure 11.

Referring now more particularly to the accompanying drawings in which-like numerals indicate like parts throughout the several views, the 15 numeral 5 designates the cylinder of the lock, which, as is customary, is preferably formed as a die-casting and has an enlarged head 6 and an eccentric latch actuating cam 'I projecting from its inner end. The cylinder is rotatably mounted 20 in a casing or mounting member 8 in which it is retained by a screw 9 having its inner projected end disposed in an annular groove Ill formed in the inner end portion of the cylinder.

At diametrically opposite portions, the casing 25 or mounting member is slotted as at I I to receive the ends of tumblers I2 carried by the lock cylinder. The tumblers are retractable by a proper key I3 in the customary manner to free the cylinder for rotation, the limits of which are defined by the engagement of either end of a rearward projection I4 extending back from the enlarged head 6, with suitable abutments (not shown) closing a portion of an annular channel I5 in the mouth of the casing.

Theftumblers in the present instance are arranged to project oppositely,`that is. adjacent tumblers are spring urged to project in opposite' directions. In the present instance, there are six tumblers arranged in three sets or pairs with 40 a single ,spring for the two tumblers of each set or p'air. Together, the tumblers ll the tumbler receiving chamber I6, which extends transversely through the cylinder, so that the adjacent faces of the-tumblers are in sliding engagement.

To facilitate relative movement between the respective tumblers, their opposite faces are centrally and longitudinally relieved or cut down as atv Il to leave two narrow guide tracks I8 which form the only areas of contact between the 50 tumblers.

As illustrated in Figures 7, 8 and 9, the tumblers are formed from rectangular bar stock and are `iirst pierced with a rectangular opening I9 and a rectangular notch or 2li at one side. The 55 keyways or recesses 20 and consequently the popierced blank is then swaged to form the depressions |1 and to form a. slanting round bottomed groove 2Iopening to one face of the tumbler. During the formation of the groove 2l, a substantial portion of the rectangular opening I9 is closed. The groove 2| which is deepest at its closed end 22, forms a pocket which cooperates with a similar pocket formed in an adjacent tumbler (in the completed lock assembly) to enclose a spring -23, which yieldably projects the two tumblersin opposite directions. f

During the swaging operation. the opposite ends of the rectangular recess 20 are pinched 'to a substantially V-shaped formation as at 24. Following the swaging operation, the ends of the tumblers are trimmed and the flashing produced by the pinching of the ends 24 is cut away to produce the completed tumbler as illustrated in Figure 9.

The recesses 20 provide the keyways of the tumblers, and as will be readily apparent, the V-shapedv ends 24 facilitate the passage of the key through the recesses.

To retain the tumblers assembled with the lock cylinder, a metal strip 25 is embedded in the cylinder with its inner edge portion projecting from one side wall of the tumbler chamber I6 into the space formed by the aligned tumbler keyways. The strip or b ar 25 limits the outward projection of the tumblers by the springs to hold the same assembled with the cylinder and also provides a guide for the key I3, being engaged by the key throughout the entire length of the key blade.

VThe front end of the strip or bar 25 projects out through .the keyway 26 and is laterally offset as at 21 so' that its outer edge breaks through the cylindrical surface of a reduced collar portiony 28 on the rear of the head 6 and the outer curved wall of the lug or projection I4, which forms a continuation of the portion 28.

As clearly shown in Figures 3 and 10, this outer edge portion of the laterally oiset end 21 has a hook 29 at its inner end, and directly aheadi of the hook, the opposite sides of the slot 30, in which the oiset end 21 of the bar is received, are swaged overv the outer edge of the oiset end to secure the bar against outward longitudinal movement.

The guide strip or bar is further held against removal from the cylinder by a finishing cap 3| clinched over the head of the cylinder. This cap `is preferably of hardened sheet metal and besides providing a neat external nish for vthe exposed end of the lock cylinder, also retainsa slidable keyway shutter 32 in place. The keyway shutter 32 is' yieldably urged to its closed position by a. spring 33 and is adapted to be opened by the insertion of the key, being moved to o ne side against the action of its spring by the eiect of the inclined depression 34 at the mouth of the keyway.

The inclined depression 34, which is` formed by pressing inwardly a portion of the cap adjacent the mouth of the keyway. also vextends 'down over the inclined inner edge 35 of the key guiding rib as clearly shown in Figure 3. Themenmation of the edge 35 serves to guide the key into proper position in the keyv ay.

By forming the key guiding rib of hardened metal, effective protection is aiorded against destruction of the lock by drilling down intp the tumblers.

As illustrated in Figure 10, the location of the sition of their ends 24 with respect to the length of the tumblers. varies in the diileren.. tumblers in accordance with combination of the lock and the contour of the opposite edges 36 of the key blade. The range of movement of the tumbler is such that those requiring a maximum lift. move more than twice the distance of -those hav- 5 ing a minimum lift, so that a tool narrow enough to lift the low tumblers cannot serve to lift the high tumblers.

'Ihe key i3 has a groove 31 extending longitudinally down one side of its blade to engage the guide bar 25. The depth of this groove, as seen from Figure 6 is greater than the major thickness of the blade. Abovel and beneath the groove, the cross section of the key blade is taperingly enlarged so that the two tumbler engaging edges y are thicker than the portions adjacent the groove 31. The wall 39 of the groove forms in effect a ridge extending longitudinally along the side of the key opposite the groove, and it is observed that the rear face of the this wall lies in the 20 plane of the adjacent face of the handle portion 49. Onv the opposite face of the key, the sides of the blade are likewise flush with the adjacent face of the handle portion 40, and as the major 25 thickness of the blade is less than the depth of the groove 31, it follows that the handle is of greater thickness than any portion Iof the blade. The shank 4I of the key is also of greater width than the blade proper. This provides greater 30 vgroove 31 is .comparatively thin. ConsequentLv,

the space left between the inner edge of the bar 35 or key guiding rib 25 and the adjacent` sides oi the tumbler keyways may be comparatively slight so that the key guiding rib practically divides the keyway into two separated chambers. This fact materially minimizes the possibility of pick- 4o ing the lock as the restriction of the'space within the keyway is such that it is impossible to operate a picking tool.

If desired, the inner edge of the key guiding rib may be provided with an additional longitudinal n 43, as shown in Figure 11, to extend across the entire keyway and contact the tumblers. In' this modication, the partition produced by the key guiding rib actually and completely divides the keyway into two separated chambers. The key used in this modification is illustrated in Figure 12, and except for the fact that the bottom wall 39 of the groove 31 is slotted as at -44, is identical to that illustrated in Figure 5.

If desired, one or more vof the tumblers may be provided with hooked ends 45 (see Figures 2 and 11). In the present instance, only .one of the tumblers is provided with such hooked ends and as shown, the sides of this tumbler beneath the hooked ends are inclined as at 46 to allow 6o the tumbler to rock during forced turning of the cylinder so that one or the other of its hooks 45 will engage over the adjacent edge of the tumbler receiving chamber in the cylinder and thus e'ectively preclude retraction of the tum- 65 bler to its retracted position.'

From the foregoing description taken in connection with the accompanying drawings. it will be readily apparent to those skilled in the art, that this invention affords a novel, sturdy lock, 70 which has maximum protection` against picking or decoding at least with any known instrument or method.

What I claim as my invention is:

i. In a lock, a lock cylinder having a keyway, 15

transversely in the lock cylinder, spring means to project said tumblers outwardly of the lock cylinder, and a key guiding rib projecting into the keyway from one side wall thereof and extending throughout the length of the lkeyway to be engageable with the tumblers to limit their outward projection.l l

2. In a lock, a lock cylinder having a keyway, a plurality of key operable tumblers slidable transversely in the lock cylinder, abutments on the tumblers, spring means to project said tumblers outwardly of the lock cylinder, and a hardened metal strip carried by one side wall ofthe keyway in the lock cylinder and having a part lying in the path of the abutments on the tumblers to limit their outward projection, said strip being so positioned as to render it diilcult to destroy the lock by drilling.

3. In a lock, a lock cylinder having a keyway, a plurality of key operable tumblers slidable transversely in the lock cylinder with portions thereof crossing the keyway, spring means to project said tumblers outwardly of the lock cylinder, and a key guiding rib extending down the keyway and projecting from one side wall of the keyway with a portion thereof lying in the path of said portions of the tumblers which cross the keyway to be engageable by said portions and thus limit their outward projection.

4. In a lock, a lock cylinder having a keyway, a plurality of key operable tumblers slidable transversely in the lock cylinder with portions thereof 'crossing the keyway, said portions of the tumblers being provided with keyways, spring means to project said tumblers outwardly of the lock cylinder, and a key guiding rib carried by one side of the keyway and lying in position to be engaged by the key engaging edges of the tumbler keyways and thus limit the outward projection of the tumblers.

5. In alock, a lock cylinder having a keyway, a metal strip embedded in one side wall of the keyway and anchored at one end against transverse displacement and protruding into the keyway to divide the keyway into substantially separated chambers, said protruding portion ofthe strip being exposed on three sides to have a direct sliding engagement with the sides and bottom of a groove in the side of a key insertable into the keyway.

6. In a lock, a lock cylinder having a keyway, a plurality of tumblers slidable transversely in the cylinder, said tumblers having keyways in line with the keyway in the lock cylinder, and a metal strip embedded in one side wall of the keyway and projecting into the keyway of the4 cylinder to guide a key for proper engagement with the keyways of the tumblers, said key guiding strip dividing the keyway substantially*l into separated chambers and being engageable by certain edges of the tumbler keyways so that the tumblers are retained assembled with the cylinder by said strip.

7. In a lock, a lock cylinder havinga transverse tumbler receiving chamber therein, a plurality of tumblers disposed in rsaid chamber, said tumblers having notches cut in one longitudinal edge `to provide keyways, and a rib carried by the cylinder and projecting from one side wall of the tumbler receiving chamber to be disposed in the keyways of the tumblers to retain the tumblers assembled 'with the lock cylinder.

8. In a lock, a lock cylinder having a transverse tumbler receiving chamber, a plurality of tumblers disposed in said chamber, said tumblers having keyways cut into one side edge thereof, spring means to yieldably project the tumblers vfrom the cylinder, and a rib carried by the cylinder and projecting from one side wall of the tumbler receiving chamber to project into the keyways of the tumblers, whereby certain edges 'of said tumbler keyways strike the rib to limit side edge to form keyways in line with the cylinder, key opening, spring means to yieldably project the tumblers from the cylinder, and a metal strip carried by the lock cylinder and extending down the key opening with a part projecting into the keyways of thetumblers so that certain edges of the tumbler keyways are engageable with the strip to limit their projection by the spring means, said strip also forming a guide for a key and restricting the space in the key opening to render picking of the lock more diicult.

10. In a lock, a lock cylinder, a plurality of tumblers carried by the lock cylinder, abutments on the side edges of the tumblers, spring means supported entirely `by the tumblers and disposed substantially on a plane passing centrally through all of the tumblers to yieldably project the tumblers from the cylinder, and means carried by the cylinder and engageable with the abutments on the side edges of the tumblers to limit their projection by said spring means.

y 11. In a lock, a. lock cylinder, a plurality of tumblers disposed in the lock cylinder, said tumblers being arranged in pairs, the tumblers of each pair having complementary recesses to form spring receiving chambers inclined with respectY chamber, said tumblers being cut away at one longitudinal side edges, and a spring receiving.

recess opening to one face of the tumbler and substantially centrally disposed with respect to the width of the tumbler.

13. In a lock, a lock cylinder having a keyway provided with a slot in one side Wall thereof, a plurality of tumblers carried by the lock cylinder, and a metal strip extending down'the keyway and set in said slot, said strip being inserted from the front end of the lock cylinder and having its outer end shaped to guide a key into proper position in the keyway and forming a support for the key throughout the length of the keyway, said strip also engaging the tumblers to retain the same assembled with the lock cylinder.

14. A plate type tumbler for locks comprising,

ya substantially flat bar having an -open recess at a, spring disposed in the groove, and said bar having an open recess to one side of the groove to aiord a keyway.

16. A plate type tumbler for locks comprising, a substantially flat bar having a spring pocket opening to one face thereof and provided by an open groove, the dept-h of which increases from, one end to the other and the deepest end being closed by an abrupt wall.

17. A plate type tumbler for locks comprising,r a substantially rectangular body having a keyway opening to one side edge and having its opposite side edges inclined from one end of the body to a point adjacent the opposite end to give the body ,a taperingly reduced width and to form abrupt shoulders adjacent said second mentioned end of the body.

18. A plate type tumbler for locks comprising a substantially rectangular body having a spring receiving pocket opening to one face thereof, said pocket having one end closed by an abrupt wall which serves as a rest for the end of a spring received in the pocket, one side edge portion of the 'body being notched to provide a keyway, and both EDWARD N. JACOBI. 15 

